Chemical mechanical polishing (CMP) is generally known in the art. For example U.S. Pat. No. 5,177,908 to Tuttle issued in 1993 describes a finishing element for semiconductor wafers, having a face shaped to provide a constant, or nearly constant, surface contact rate to a workpiece such as a semiconductor wafer in order to effect improved planarity of the workpiece. U.S. Pat. No. 5,234,867 to Schultz et. al. issued in 1993 describes an apparatus for planarizing semiconductor wafers which in a preferred form includes a rotatable platen for polishing a surface of the semiconductor wafer and a motor for rotating the platen and a non-circular pad is mounted atop the platen to engage and polish the surface of the semiconductor wafer. Fixed abrasive finishing elements are known for polishing semiconductor layers. An example is WO 98/18159 PCT application by Minnesota Mining and Manufacturing.
An objective of polishing of semiconductor layers is to make the semiconductor layers as nearly perfect as possible. Fixed abrasive finishing pad finishing surfaces can suffer from being overly harsh on a workpiece causing unwanted scratching or other unwanted surface damage thus reducing the perfection of the surface. Further, a fixed abrasive finishing pad finishing surface can suffer from having a higher than necessary friction when finishing a workpiece. This higher than necessary friction can lead to other unwanted surface damage. Further, fixed abrasive finishing pads can have abrasive particles unexpectedly break away from their surface during finishing and these broken away abrasive particles can scratch or damage the workpiece surface. Still further, during finishing a particle can break away from the workpiece surface forming a workpiece abrasive particle which can scratch or damage the workpiece surface. These unwanted effects are particularly important and deleterious to yield when manufacturing electronic wafers which require extremely close tolerances in required planarity and feature sizes.
It is an advantage of this invention to reduce the harshness of fixed abrasive finishing pads on the workpiece surface being finished. It is an advantage of this invention to reduce unwanted scratching or other unwanted surface damage on the workpiece surface during finishing. It is further an advantage of this invention to reduce the friction during finishing to help reduce unwanted surface damage. It is an advantage of this invention to reduce unwanted damage to the workpiece surface when during finishing with a fixed abrasive finishing element an abrasive particle unexpectedly breaks away from their surface. It is an advantage of the invention to reduce unwanted damage to the workpiece surface when an abrasive workpiece particle breaks away workpiece surface during finishing. It is further an advantage of invention to develop new control methods for lubricated finishing including methods to improve a process control model. It is further an advantage of this invention to help improve yield for workpieces having extremely close tolerances such as semiconductor wafers.
These and other advantages of the invention will become readily apparent to those of ordinary skill in the art after reading the following disclosure of the invention.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer having a semiconductor wafer surface comprising a step of providing a finishing element finishing surface comprising a polymer; a step of positioning the semiconductor wafer surface proximate to the finishing surface; a step of providing an organic lubricant proximate to the surface of the semiconductor wafer surface being finished; a step of applying an operative finishing motion in an interface between the semiconductor wafer surface and the finishing element finishing surface; and wherein applying the operative finishing motion forms an organic lubricating film layer of at most 10 molecules thick which self-assembles with and adheres to the semiconductor wafer surface being finished.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising a step of providing a finishing surface comprising at least in part an organic polymer; a step of providing a control subsystem having a plurality of operative sensors, a controller, and a processor having access to look-up tables and historical performance; a step of positioning the semiconductor wafer surface proximate to the finishing surface; a step of providing an organic lubricant between the finishing surface and the first and second uniform region surfaces of the semiconductor wafer surface; a step of applying an operative finishing motion that transfers the organic lubricant from the finishing surface to an interface comprising the finishing surface and the first and second uniform region surfaces forming a self-assembling organic lubricating film on at least the first uniform region surface; a step of sensing progress of finishing information with the plurality of operative sensors; a step of determining a change to a process control parameter using progress of finishing information, the look-up tables, and the historical performance; and a step of changing the at least one process control parameter in a manner that changes the coefficient of friction in at least one of the first and second uniform region surfaces during at least a portion of the finishing cycle time.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer surface having a uniform region surface comprising a step of providing a finishing surface; a step of providing an organic lubricant between the abrasive finishing surface and the conductive region surface; and a step of applying an operative finishing motion between the semiconductor wafer surface and the finishing surface forming a organic lubricating film of at most 10 molecules thick on the conductive region of the semiconductor wafer surface wherein the operative finishing motion forms a friction in the interface between the conductive region on the semiconductor wafer surface and the abrasive finishing surface; and the organic lubricating film interacts with and self-assembles with the uniform region surface to reduce the coefficient of friction.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer having a semiconductor wafer surface and a tracking code comprising a step of providing an finishing element finishing surface; a step of providing an organic lubricant to an interface between the finishing element finishing surface and the semiconductor wafer surface; a step of providing a control subsystem having a processor, a plurality of operative sensors, and a controller and wherein the processor has access to access to the tracking code, look-up tables, and a control logic consistent with the current manufacturing step; and a step of applying an operative finishing motion to the interface between the abrasive finishing element finishing surface and the semiconductor wafer surface forming an organic lubricating film which adheres to at least a portion of the semiconductor wafer surface; a step of sensing a first progress of finishing information with the plurality of operative sensors; a step of determining a change to at least one process control parameter at least in part using the progress of finishing information, the tracking code, look-up tables, and the control logic consistent with the current manufacturing step; a step of changing the at least one process control parameter; a step of sensing a second progress of finishing information with the plurality of operative sensors after changing the at least one process control parameter; a step of storing at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer surface having uniform regions, the method comprising a step of providing an finishing element finishing surface; a step of providing an organic lubricant to an interface between the semiconductor wafer surface and the finishing element finishing surface; and a step of applying an operative finishing motion forming a marginal organic lubricating film on at least a portion of the semiconductor wafer surface and wherein the operative finishing motion forms a friction in the interface between the uniform regions of the semiconductor wafer surface and the finishing element finishing surface; a step of self-assembling of a marginal organic lubricating film with the uniform regions of the semiconductor wafer surface during at least a portion of the finishing cycle time; a step of sensing in situ finishing information with at least one operative sensor; and a step of controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least two different uniform regions of the interface between the semiconductor wafer surface and the finishing element finishing surface in response to an in situ control signal during at least a portion of the finishing cycle time.
A preferred embodiment of this invention is directed to a method of finishing of a semiconductor wafer surface having a first uniform region surface and a second uniform region surface comprising a step of providing a finishing element finishing surface; a step of providing an organic lubricant to an operative finishing interface; and a step of applying an operative finishing motion to the interface formed between the finishing element finishing surface and the first and second uniform region surfaces forming a marginal organic lubricating film on at least the first uniform region surface and wherein the operative finishing motion forms a friction in the interface between the semiconductor wafer surface and the finishing element finishing surface and the marginal organic lubricating film self-assembles with and adheres to at least the first uniform region; and a step of controlling the marginal organic lubricating film by changing at least one control parameter in a manner that changes the coefficient of friction in at least the first uniform region in response to an in situ control signal during at least a portion of the finishing cycle time; and a step of inducing differential tribochemical wear to at least a portion of the semiconductor wafer surface.
A preferred embodiment of this invention is directed to a method of finishing a semiconductor wafer having a semiconductor wafer surface and a tracking code comprising a step of providing an finishing element finishing surface; a step of providing a finishing aid to an interface between the finishing element finishing surface and the semiconductor wafer surface and wherein the finishing aid is selected from the group consisting of a lubricating aid and chemically reactive aid; a step of providing a control subsystem having a processor, a plurality of operative sensors, and a controller and wherein the processor has access to access to the tracking code, look-up tables, and a control logic consistent with the current manufacturing step; and a step of applying an operative finishing motion to the interface between the abrasive finishing element finishing surface and the semiconductor wafer surface forming a reaction between the reactive finishing aid and the semiconductor wafer on a portion of the semiconductor wafer surface; a step of sensing a first progress of finishing information with the plurality of operative sensors; a step of determining a change to at least one process control parameter at least in part using the progress of finishing information, the tracking code, look-up tables, and the control logic consistent with the current manufacturing step; a step of changing the at least one process control parameter; a step of sensing a second progress of finishing information with the plurality of operative sensors after changing the at least one process control parameter; a step of storing at least in part the first progress of finishing information, the second progress of finishing information, the tracking code, and the control logic consistent with the current manufacturing step which was used.
Other preferred embodiments of my invention are described herein.